Motion-picture apparatus



March 11, 1930. J, PRQKSA L749,779

MOTION PICTURE APPARATUS Filed March 2l, 19525 145e Sheets-Sheet 3 March 11, 1930. l PRQKSA 1,749,779l

MOTION PICTRE APPARATUS Filed March 21, 1925 14 Sheets-Sheet 4 March 1930.

MOTION PICTURE APPARATUS Filed March 21, 1925 14 Sheets-Sheet '7 f f f f March 11, 1930. j. PRQKSA MOTION PICTUR APPARATUS Filed March 2l, 1925 l@ Sheets-Sheet 8 March 11, 1930. 1. PROKSA "1,749,779

MOTON PICTURE APPRATUS Emea Maron 21, 1928" 14 sheets-sheet 9 @QQ Q- Mach lll, 1930. J. PROKSA 1,749,779

MOTION PICTURE AFPARATU$ Filed March 21, 1925 Mgshets-sheet 1o .Filed Mam 21, 1925 14 sheets-sheet 11 March 11, 1930. J. PRoKsA MOTION PG'I'UREfY APPARATUS Filed March 21, 1925 14 sheets-snaai 15 Mii/6.55 @5;

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lMarch 1l,` 1-930. 4 VJ, PROKSA 1.749,779

MOTION PICTURE APPARATUS Y Filed March 2l. i925 14 Sheets-Sheet 14 `Patented Mar. 1i,

UNITED STATE..

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JOHN PROKSA, OF CECAGO, ILLINGIS, .ASSEGNOR TO HELGS ORF'OBATIION, F CHICAGO', LLINOIS, CORGRATOI GF UELAJAR-E MOTIN-E'IECTURE APPARATUS Application led Merch 21, 1925.

My invention relates to improvements in motion picture projecting apparatus and has among its other objects the production of apparatus of the kind described, which is simple, convenient, compact, durable, reliable, eilicient and satisfactory for use wherever found applicable. A particular object oi the .invention is to provide apparatus of the kind described which is readily accessible for inf spection, repairs or adjustment. Another particular object of the invention is to pro vide motion picture projecting apparatus which may be adjusted While in operation to control its speed, the framing of the pictures, the shutter, etc., so that there will be no loss of time in adjusting the apparatus after the initial picture or title of a ilm has been flashed upon the screen. Many other objects and advantages of the construction herein shown and described Will be obvious to those skilled in the art from the disclosures herein given. To this en'd my invention consists in the novel construction, arrangement and combination of parts herein shown and described, 2 and more particularly pointed out in the claims.

In the drawings, wherein like reference characters indicate like or corresponding parts: Fig. 1 is a plan view of apparatus embodying the invention;

Fig. 2 is a side elevation looking from the left of the apparatus shown in Fig. 1;

4Fig- 3 is a. section taken on line 3-3 of Fig. 1;

Fig. 4 is a side elevation looking from the right of the apparatus shovvn in Fig. 1; I

Fig. 5 is a rear elevation of the apparatus shownin Fig. 1;

Figs. G, 7 and 8 are sections taken on line 6-6, 7-7 and 8`8, respectively, of Fig. Figs. 9, 10 and 11 are sections taken on line 9--9, 10-1O and ll--11, respectively, of

4J Fig. 12 is a section taken on line 12-12 taken on line 13-43 o- Serial No. 17,336.

Fig. 15 is a section taken on line 15-15 of vro L 1g. lu

9 .Fig 16 is a section taken on line 16-16 of n l5;

Fig 17 is a section taken on line 17-17 of nig. 6 5

Fig. 18 is an end elevation looking from the left of the apparatus shown in Fig. 17;

Figs. 19, 2O and 21 aresectionstaken on line 19-19, 20-20 and 21-21, respectively', of Fig. 17 u Fig. 2L is a section taken on line 22-22 of Fig. 5; w Fig. 23 is a section taken on iine 23-23 of Fig. 2;;

Fig. 24 is a section taken on line 24-24 of Fig. 12; and

Fig. 25 is a section taken on line 25-25 of Fg 12.

Referring for the present to Figs. l to 4, in-

clusive, the reference character 30 designates generally a frame or housing which encloses the major portion of the moving` parts and is a part of my improved motion picture proj ecting apparatus and comprises a. bottoni plate 31, a toplplate 32, a front Wall 33, a side Wall 34 and a rear Wall 35, the several enumerated plates and Walls being preferably formed integral with each other. Projecting inwardly from the front Wall 33 and preferably formed integral therewith is a tubular boss 37 adapted to accommodate a plurality of lenses, as Will presently appear. The side wall 34 and the rear Wall 35 do not entirely close the rej spective side and rear ends ol vthe housing 30, the opening in the side Wall 34 being normally closed by a door 88 hinged to the front wall 33 by a hinge 39 6). To hold the door 38 in its closed position, a spring latch inember 41 secured to the door engages a shoulder 42 formed upon a panel 43, which, together With a door 44 normally closes the openingin the rear Wall 35. The panel 43 is removably secured to the top plate 32 and the rear .vall 35 by spring clips 4G or the equivalent adapted to engage the rear Wall and a flange 47 projecting downwardly Jrom the top plate 32. is shown in Fig. 15, each spring clip 4G is apertured, as at 48, to tit snugly upon a reduced portion 49 ofa bolt 50 rotatably journaled in the panel 43. It will be noted that the reduced portion 49 is flattened, as at 52, to prevent angular displacement ofthe spring clips 46 relative to the bolt 50. A screw 54 secures each spring clip 46 to its respective bolt 50. To reinove the panel 43 from the housing it is only necessary to rotate each of bolts 50 through 18()O whereupon the spring clips 46 will be disengaged from the top plates and rear wall.

The door 44 is mountedupon the anel 43 by hinges 56 and 57 and is provide vwith av light projecting aperture 59, the. lighting apparatus being positioned immediately'behmd said aperture. The lighting apparatus is not shown since it forms no lpart of this invention. The door 44 is protected from the heating effect of the light by a cooling plate 60, which is rigidly secured to the door by bolts or screws 61 (Fig. 12). The movement of the door 44 may be limited by a keeper 64 rigidly secured to the door and adapted to engage the downwardly projecting flange 47 when the door is swung to its open position (Fig. 9).

Pivotally mounted in a bracket 65 secured to the lower portion of the door 44 is a latch member 66 adapted to engage the upper edge (Fig. 13).

of the rear wall 35 when the door is in its closed position. A compression spring 67 disposed in the bracket 65 yieldingly holds the latch member 66 in engagement with the rear wall 35.

That side of the housing 30, which is disposed directly opposite the side wall 34 is normally closed by a corner plate70 andadoor 71, the corner plate 70 being secured by screws 72 to the bottom plate 31 and the front wall 33, and the door 71 being mounted upon the front wall 33 by a hinge 74. Pivotally mounted in a bracket 75 secured to the outer surface of the door 71 is a latch member 76 which is yieldingly urged by a spring 77 into a position wherein it will engage a keeper 78 secured to the inner surface of the door 44 It will be noted that the latch member 76 and its associated spring 77 are similar in construction to the latch member 66 and the spring 67, the latch members being so constructed that if their outer ends are depressed the doors 44 and 71 may be swung open. The door 71 is provided with a rtransparent panel 79 through which the operator may view the operation of the film feeding mechanism.

From the foregoing description of -the housing 30, it is apparent that access may be readily had to the film feeding mechanism enclosed therein as the doors 38, 44 and 71 may be brought into their openrpositions with little effort on the part of the operator. and the panel 43 together with the door 44 may be removed by rotating the bolts 50 to disengage the spring clips 46 from the flange 47 and the rear wall 35.

end of the bracket arms 81 and 82 is a shaft 85 having a rack 86 cut in one end thereof. Slidably journaled upon the shaft 83 is a 'bracket 88 which is rigidly secured to the shaft 85 by set screws 89. The bracket 88 is adapted to support an electrical motor which is adjustably secured to the bracket by means of bolts 92 passing through slots 93' formed in the bracket. The motor 90 'is provided with a shaft 94 to which is rigidly secured a friction disk 95 adapted to be brought into and'out of driving engagement with yfriction disks 97 and 98 mounted upon a shaft 100. The shaft 100 is slidably journaled in a tubular shaft 102, which is rotatably journaled in a bearing bracket 101 secured to the side wall 34 and in a cap member 103 secured to the bracket 101.

The means for bringing the friction disk 95 into and out of driving engagement with the -friction disks 97 and 98 comprises a pinion 104, which meshes with the rack 86 and is secured to a shaft 105 rotatabl journaled in the motor support 80. A han wheel 106 secured to the shaft 105 may be employed to rotate the shaft 105, which, in turn, will rotate the pinion 104 and cause the shaft 85 to move along its longitudinal axis. Such movement of the shaft 85 will be accompamed by a corresponding movement of the motor 90 and the friction disk 95, the motor 90 being secured to the bracket 88, which is, 1n turn secured to the shaft 85 by set screws 89. It is obvious that the speed at which the shaft 100 is rotated may beincreased or decreased by moving the friction disk 95 away from or toward the axis of rotation of the shaft 100. T he speed at which the shaft 100 rotates may also be controlled by a brake 1ever 109 pivotally mounted intermediate its ends upon a pin 110, which projects from a. boss 111 formed upon the motor support 80. One end of the lever 109 is adapted to frictionally engage a brake drum 113 formed upon the friction disk 98. This construction is advantageous in that the operator may ma- 'nipulate the brake lever 109 to control the disk 97 is rigidly secured to the shaft 109 by a set screw 119 and the friction disk 98 is rigidly secured to the tubular shaft 102 b v a set screw 120. The friction disk 93 is constrained to rotate with the friction disk 97 by pins 122 rigidly secured in the friction disk 97 and slidably engaging` bores 12?; formed in thelfriction disk 98. 'Formed integral 4with Ithe tubular shaft 192 is a gear 125. which urges the friction'disk 97 toward the friction disk 98 may be varied by manipulating nuts 134 which are threaded upon thesshaft 100 and against which the collar rests. The inner end of the shaft 100 rides upon a cam 136, which is rigidly secured to a shaft 137 rotatably journaled in the housing 30. Se-

` cured to the, outer end of the shaft 137 is a lever 138 having an arcuate recess 139 formed in the inner face thereof. A pair of shallow depressions 140 and 141 formed in the bottom of the arcuate position 139 are engage able by a ball 143 which is yieldingly urged toward the lever 138 by a compression spring 144. The ball 1113 is slidably mounted in a plug 145 projecting from the rear wall 35. l/Vhen the ball 143 is resting in the depression 14() the shaft 137 will beheld in a position wherein the cam 136 will permit the friction disk 97 to be held in frictional engagement with the friction disk SiS-bythe spring 130.

' When the lever 138 isniovcd into a position wherein the ball 14.3 will rest in the depression 1417 the cam 136 will be brought into a. position wherein it will prevent the friction disk 97 from engaging the friction disk The above described mechanism associated with the motor 90 and operatively connecting the motor to the pinion 128 is more fully shown and described in my (3o-pending application No. 17,337,- filed March 2l, 1925.

Referring now to Fig. 11. the pinion 128 meshes with a gear 150 secured upon a shaft 151 which is rotatably `iournahul in a lug 152 formed upon the frontwall 33; Ono cud ofv the shaft 151 projects through the corner plate and is adapted to receive a crank or the like whereby the operator may drive the film feedinginecha'uism, if, for any reason. he does not desire to use the motor 99. or if the motor is not available. Meshing with the gear is a gear 156. which is rotatably 3ournaled upon a pin 157 projecting from a boss 158 formed upon a partition 160, the partit-ion 160 extending from the front wall 33 to the rear wall 34 and being formed integral therewith. The gear 156 meshes with a pinion 161 secured to a shaft 162 which is -rotatably journalcd in a bearing formed in the partition 160 and has rigidly secured to it a lihn take-up sprocket drum 164. Also secured to the shaft 162 is a sheave 163 whereby a take-up reel (not shown) may be driven.

- bevel gear 165 formed integral with the gear 159 meshes with a bevel gear 166 rigidly secured upon thc lower end of avertically disposed shaft 168. rl`hc shaft 168 is rotatably journaled in lugs 169- and 170 formed upon the. front wall 33. Also secured to the lower end of the vertically disposed shaft 168 is a spur gear 172 which meshes With an elongated pinion 173 secured to the lower end of a vcrtically disposed shaft 175. The construction is such that the shaft 175 may be moved along its longitudinal vaxis without withdrawing the pinion 173 from operative engagement with the spur gear 172.

Formed integral with the spur gear 172 a bevel 177 which meshes with a bevel 178 secured to a shaft 179 which'is rotatably journaled in a bracket 181 mounted in a hollow boss 183 )rejecting from the front wall 33. The bracket 181 is rotatably journaled in the hollow boss 183, the bracket 181 being provided with an annular flange 18a seated in a recess 185 turned in the outer end of the hollow boss. A collar 186 secured to the hollow boss 183 by screws 188 engages the annular flange 181 and prevents withdrawal of the bracket 181 from the boss. 1t will be noted that the axis of rotation of the bracket 181 is coincident with the axis of rotationiof the shaft 179. linned to the outer end of the shaft 179 is a pinion 190, which meshes with a pinion 191 pinned to a shaft 192 rotatably journaled in the bracket 181 and iu a cap 193 fixed to the bracket` the axis of the shaft 192 being ecccntricallv disposed with respect to the axis of rotation of the bracket. shaft 192 is a shutter 191 which preferably comprises two diametrically disposed fanshaped blades 195 and 196. the shutter being mounted upon a. spider 197 having a. split hub 198. A collar 199 seated upon the hub 198 is provided with a set screw 200` whereby the split hub 198 may be clamped to the shaft 192 as shown in Fig. 141. The narrow portions of the fan-shaped blades 195 and 196 are disposed adjacent the axis of rotation of the shutter so that the blades increase in width toward the outer ends thereof. When the apparatus is in operation the blades 195 ald 196 will alternately intercept the beam of light projected upon the screen in a manner well known to those skilled in the art, one of the blades being` adapted to intercept the beam of light when the film is being advanced and the other blade being adapted to inter` cept the beam of light during that time a Carried b v the outer end of theV l laterally adjusted`positions in which the (Fig. 9).

shutter 194 occupies adjusted positions with respect to the light projecting aperture 59. The arrangement is such that the shutter 194 may be made to synchronize with the intermittent motion of the film so that the beam of light willbe intercepted during the Ventiretime the film is in motion.

A handle 205 secured to the bracket 181 provides means whereby the operator may shift the bracket into the desired position. The bracket 181 may be secured in the desired position by a post 207 threaded intothe hollow boss 183 and provided with a shoulder 208 adapted to cause the collar 186 to clamp the fiange 184 against the hollow boss. The post 207 is provided with a handle 210, whereby it may be readily manipulated.

Rigidly securedte the upper end of the vertically disposed shaft 168 is a spiral gear 212, which meshes with a spiral gear 213, which is formed upon a tubular member 214. Also formed upon the tubular member 214 is a pinion 216, which meshes with a gear 217 secured to a shaft 218 rotatably journalefl in a boss 220 formed integral with the partition 160. Securedto one end of the shaft 218 and aligned with the take-up sprocket drum l 164 is a feed sprocket drum 222. Vhcn the apparatus is in operation the sprocket drums 164 and 222 are continuously driven and are adapted to withdraw the film from a supply reel (not shown) positioned above 'the housing 30.

Cooperating with each of the sprocket drums is a plurality of grooved rollers 224 adapted to hold the film in proper engagement with the teeth of the sprocket drums The grooved rollers 224 are rotatably mounted upon pins225 and 226 carried by a lever 227 which is pivotally mounted upon one of a plurality of pins 229 projecting from the partition 160. Each lever 227 is provided with two angularly disposed surfaces 231 and 233 engageable by a hollow pin 234 which is slidably urged toward the angularly disposed surfaces by a compression spring 236, the compression spring 236 being disposed in a hollow boss 237, which projects such that when a pin 234 is in engagement with the surface 231 the grooved rollers 224 will hold the film in mesh with the associated sprocket drum, and when the pin 234 is in engagement with the surface 233 these rollers .-224 will be held in the positions wherein the are shown in dotted lines in Fig. 9. Eac

grooved roller 224 is provided with a flange 240 adapted-to engage an edge of the film so as to align the vfilm with'the sprocket drums. Associated with each sprocket drum 164 and 222 is a plate 243 secured to a pin 244 projecting from the partition. The plates 243 are adapted to strip the film from the sprocket drums in the event that the film tends to adhere thereto.

' Referringnow to Fig. 11, the aforementioned shaft 175 is rotatably mounted in a casing 245 and in a cap 246, which is secured tothe casing by screws 247, ball bearings 248 and 249 being provided for this purpose. The ball bearing 248 has its outer .race secured in a bushing 246 which is rotatably mounted in a bore 248b formed in the cap 246, ,the ball bearing being eccentrically disposed with respect to the longitudinal axis of the bore. One race of the ball bearing 249 is secured in a bushing 249a rotatably journaled in a bore 249* formed in the casing 245. The ball bearing 249 is eccentrically disposed with the longitudinal axis of the bore 249". The bushings 248a and 249 are provided with levers 248C and 249, respectively, whereby the bushings may be rotated to adjust mechanism hereinafter described. Mounted upon the shaft 175 are cams 250 and 251, the cam 251 being keyed to the shaft 17 5 and being held against longitudinal displacement relative to the shaft by collar 253 formed upon the shaft and by a collar 254 driven upon the shaft. The cam 251 is disposed in a well 256 formed'in the lower portion of. the casing 245, the well 256 being provided with a closure plate 257 and being adapted'to hold any suitable lubricant. The cam 250 is splined upon the shaft 175 and is disposed in a well 260 formed in a casing 261 provided with a cap 263, the well 260 being also adapted to hold a supply of lubricant. A sleeve 264 threaded into the cap. 263 and a ball bearing 266 interposed between tbe cam 25() and the casing 261 prevent longitudinal displacement of this cam relative to the casing 261. The cam 250 and the casing 261 with its cap 263 may move as a unit up and down upon the shaft 175, the

cam being constrained to rotate with the shaft. The cams 25() and 251 are preferably of the type disclosed in my U. S. Patent #1,170,991 of February 8, 1916, and each cam is provided with a pair of oppositely inclined counterpart grooves 270 adapted to be engaged and traversed by a plurality of prongs 271 radially disposed upon one of a plurality of star wheels 273 and 274, the star wheel 273 being associated with the cam 250 and the star wheel 274 being associated with the cam 251. rllhe cams 25C* and 251 may be accurately aligned with the star wheels 278 and 27 l1, respectively, by manipulating the levers 218c and 2429?' to move the shaft 175 relatively to the star wheels.

As clearly described in the aforementioned patent, each revolution ot one ot the cams 250 and 251 is accompanied by rotation oi' the associated star wheel through an angle ot 90 degrees, so that when the cams 250 and 251 are continuously driven the star wheels 278 and 274 will be intermittently driven. However, the present invention is not limited to cams and star wheels of the described construction as any equivalent structure may be employed. The star wheels 278 and 27aare preferably secured to shafts 278 and 277, respectively, the shaft 276 being rotatably journaled in the casing 261 and the shaft 27,7 being rotatably journaled in the casing` 245. Secured to the shafts 27 6 and 277, respectively, and aligned with the sprocket drums 164 and 222 are sprockets 280 and 281 tor intermittently advancing the iilm.

The casing` 215 is slidably journaled upon a pair of vertically disposed pins and 285 and may be raised and lowered by means comprising a lever 286, which is secured to a shaft 287 ,pivotally mounted in the liront wall 88, the shatt 287 having lever 288 se cured to its inner end, which lever 288 carries an anti-friction roller 289 engaging a groove 290 formed in the casing 2415. rl`he pins 284 and 285 arel provided with hexagonal heads 28aa and 285% respectively, adapted to receive a wrench or the like and they are screw threaded into the top plate 82. Lugs 288 formed upon the Yfront wall 88 are apertured to receive the shank portions ot the pins 284 and 285. The antiriction roller 289 is journaled upon a pin 291 mounted. in the free end or the lever 288. Secured to a lug 800 termed upon the 'front wall 88 is one end of a helical spring 801, which is trained over a sheave 802 and has its other end secured to the pin 291. The sheave 802 is journaled upon a pin 802fL projecting from the front wall 88. This construction is more clearly shown and described in my Patent No. 1,708,521, issuedI April 9, A1929, the arrangement being such that the spring 801counterbalances the casings 24:5 and 281 and the mechanism carried thereby. lt willbe readily understood, however, that. the lever 287 may be manipulated to raise and lower the casings 2&5 and 281 and the mechanism carried thereby as a unit and that the sprockets 280 and 281 may be brought int-o a plurality ot adjusted posi` tionswith respect to a light projecting aperture 808 formed in a plate mounted upon the inner side of the door ist 12). rl`his is to permit the pictures to be properly framed upon the screen.

Projecting through the casing 281 and rign idly secured 'thereto a pair ot vertically disposed pins 80G and 807, which are slidably journaled in the casing 245 and the cap 2116. Compression springs 808 disposed around the pins 808 and 807 are interposed between the casings 2&5 and 218 and tend to hold the casing 182 in a position wherein the sleeve bears against the inner race of the ball hearing 218. This construction permits the sprockets 280 to be moved toward the sprochu ets 281 when film is be threaded through the apparatus so that the springs 808 may afterwards increase the distance between the sprockets 280 and 281 to draw the lm taut. lhe lilni is held in engagement with the teeth of the sproclrets280 by'a pair ot grooved rollers 810 having flanges 811 adapted to engage theedges oit the iilm. ln a like manner the tilni is held in engagement with the teeth of the sprockets 281 by a pair oi' grooved rolln ers 818 having flanges 8141 adapted to engage the edges of the lilm. The grooved rollers 810 are rotatably iournaled upon a pin 815 carried in braclret 818 which is pivotally mounted upon a pin secured in a pair oit lugs 81Q Yformed integral with the casing 281. The rollers 810 maj be swung` out ot their functionally operat .e positions whenever a iilm is to be 'threaded through the apparatus. 1 leaiE spring 820 secured to the casing 281 is adapted to yieldingly hold the bracltet in or out ci the position wherein the rollers 810 are operatively engaging the sprockets 280. rTElie position which the rollers 810 will assume with respect to the sprockets 280, when they are in their functionally operative positions, is adjustable to a relatively small extent by a screw 82d which may be manipulated to move 'the rollers with respect to the sprockets. o

The grooved rollers 818 are carried by a pin 828 mounted in a threading lever or bracket 827 which is, in turn, pivotally mounted upon a pin 828, the pin 828 being rigidly secured in a pair of lugs 829 formed upon the casing 2415. lhe rollers 818 may be swung into and out of their 'functionally onerative positions with respect to the sprockets V281. il leatspring 880 secured to the casing 245 is radapted to yieldingly hold the bracl-:et 827 in or out of the position wherein the rollers 818 are operatively engaging the sprockets 281. The 'functionally operative position of the rollers 818 may be varied by manipulating a screw 882. .f1 plate 8841- secured to the casing will strip the lm from the sprockets 281 if the film tends to adhere thereto.

Secured to the bracket 827 is a plate 8110 having a cam slot 8%1 which rides a pin 8112 projectingjfrom a lug 8411 formed integral with the casing 2115. The cam slot 8111 is so designed that when the rollers 818 are brought into their. functionally inoperative positions with respect toy the sprockets 281,

the casing 261 will be drawn toward the casing 245 against the action of the springs 308. This, as hereinbefore explained, permits the film to be trained over the sprockets 280 and 281 in such manner that when the rollers 313 are restored to their functionally operative positions the strip of film bet-Ween the sprockets 280 and the sprocket 281 is suitably tensioned.

The above described mechanism closely associated with the sprockets 280 and 281 is more clearly shown and described in my Patent No. 1,708,521, issued April 9, 1929.

An best shown in Fig. 12, a plate 346 is positioned intermediate the sprockets 280 and 281, the plate 346 being in close proximity to the plate 304 when the door 44 is in its closed position. During the operation of the apparatus the film passes through the slotA so formed between the plates 304 and 346. The plate 346 is provided with a` light projecting aperture 347 aligned with the aperture 303 and designed to cooperate with the aperture 303 to frame the pictures. The plate 346 is secured to a tubular member 348 by screws 349, the tubular member 348 being detachably secured to an aperturcd cap 350 closing the inner end of the tubular boss 37. The means for securing the tubular member 348 to the apertured cap 350 comprises a plurality of pins 352 rigidly secured in and projecting from the tubular member 348. Each pin 352 projects into the cap 350 and is provided with an inclined annular shoulder 354 engageable by the pointed end 355 of a screw 356, the

screw 356 being threaded into the apertured cap 350. It is obvious that the screws 356 mayl be manipulated to draw `the tubular member 348 tightly against the apertured cap 350.

The tubular boss 37 is provided with an outer bore 360 and an inner bore 361, the inner bore 361 being of less diameter than the outer bore 360. Slidably journaled in the inner bore 361 is a tube 363 which has its outer end rigidly secured to a tube 364 slidably journaled in the outer bore 360. Secured in the tube 364 is a sleeve 365 which is secured to a sleeve fitted into the tube 363, a collar 367 being interposed between the sleeve 365 and the sleeve 366. A lens 370 is mounted in the sleeve 365 and a lens 371 is mounted in the sleeve 366. A circnmferentially disposed slot 373 formed in the tube 364 is engageable by a pin 374 projecting from a vertically disposed shaft 375 which is rotatably journaled in the housingr 30, the pin 374 being eccentrically mounted with respect to the axis of rotation of the shaft 375. The shaft 375 is held a ainst longitudinal displacement by a pin 3 7 which rides in an annular groove 379 formed in the lower end of the shaft. A leaf spring 380 secured to the outer surface of the front wall 33 yieldingly holds the pin 377 in engagement with the annular groove 379, the

pin being provided with a head 382, whereby the operator may withdraw the pin from the groove so that the shaft 375 may be withdrawn from the apparatus. Secured to the upper end ofl the shaft 375 is a lever 384, whereby the shaft 375 may be oscillated to focus the lens 370 and the lens 371, it being apparent that oscillation of the shaft will be accompanied by longitudinal movement of the tubes and 364 and the sleeves 365 and 366.

Carried by the door 44 and disposed intermediate this door and the plate 304 Yis a fire door 386, which is pivotally mounted upon the door 44 b v means of a pin 387, the fire door 386 being of suilicient size to close the light projecting aperture 59 formed in the door 44. Formed integral with the lire door 386 is an arm 390 from which projects a pin 391. The pin 391 rides in a slot 392 formed in one end of a lever 393 which is pivoted intcrn'lediate its ends upon the door 44, a screw 394 being provided for this purpose. When the door 44 is in its closed position, the other-end of the lever 393 is engagcable by a pin 396 projecting from the free end of a lever 397 which is rigidly secured t'o one end of a shaft 398 rotatably ournaled in bosses 400 formed upon the partition 160. Secured to the other end of the shaft 398 is a lever 402, the free end of which is engageable by a pin 403 slidably j ournaled in a sleeve 404, one end of the sleeve 404 being secured in a collar 405, which is pinned to the inner end of a tubular boss 407 projecting from the partition 160. The pin 403 is flattened as at 408 to slide in a like shaped aperture 409 formed in a bushing 410, the bushing 410 being fixed in one end of the sleeve 404. This construction prevents rotation of the pin 403 around its longitudinal axis. The sleeve 404 rotatably journals the aforementioned tubular member 214, the tubular member 214 having secured thereto at its outer end a collar 412 having an annular flange 413. Pivotally mounted in the flange 413 are a pair of bell crank levers 415, each bell crank lever comprising arms 416 and 417. Each arm 417 carries a weight 418 and.

each arm 416 is provided with an extension 420 engaging a bore 422 formed in a collar v423 which is journaled on the outer end of the pin 403. A plurality of tension springs 419 tend to draw the weights 418 toward each other. When the apparatus is in operation, the centrifugal force generated by the weights 418 will cause the bell crank lever 4,15 to push the pin 403 in a direction which will rotate the shaft 402 in a clockwise direction (Fig. 17). The shaft 402, when so rotated, will cause the pin 396 carried by the lever 397 to angularly displace the lever 393 in a counterclockwise direction (Fig. 13). This displacement of the lever 393 will cause the fire door 386 to move to the position wherein it is shown in dotted lines in Fig. 13, thus permitting 

